JPH02103005A - Device for varying distance measuring range - Google Patents

Abstract

PURPOSE:To relatively widen a distance measuring area as to allow exact photographing by variably providing a field frame and zooming a photographic lens to the angle of view of the small field frame after distance measurement. CONSTITUTION:The photographic lens 1 has a zoom function by which the focal length can be varied. The display of the field frame and the distance measuring area is provided variably in size by an LCD or ECD to a display device 4 provided to the real image plane of the finder system. The photographic lens 1 is zoomed to the angle of view equal to the angle of view of the small frame of the field frame after the distance measuring operation of the focus detector in this constitution. The effect equal to the effect of widening the distance measuring area is obtd. easily in this way without changing the size of the distance measuring module. In addition, this device is advantageous in terms of space in designing the camera.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance measuring range variable device for a single-lens reflex camera having a zoom ajrI4.

[Prior art] In a single-lens reflex camera, if the focus detection (distance measurement) area is expanded, it becomes possible to measure the distance even if the main subject is off the center of the viewfinder screen, which increases the freedom of composition. It increases and becomes suitable.

However, in order to expand the distance measurement area, it is usually necessary to increase the shape of the distance measurement module, which has a distance measurement optical system and a light receiving section using a CCD, which requires changes in its shape, camera configuration, and design. It was becoming difficult.

The applicant has previously proposed that the focal length of the photographing lens be set to the wide end during focus detection compared to when shooting, in order to expand the distance measurement area, but in this proposal, the photographer's manual It is designed to return to the original focal length from the focal length or wide end depending on the operation, and there is no mention of the relationship between the focus detection area when observing the viewfinder for focus detection and when shooting. , it is difficult to understand the correspondence between the field of view frame in the viewfinder and the actual shooting range.

[Invention or Problem to be Solved] The present invention was made in view of the above background, and it is possible to easily expand the distance measurement area without changing the size of the distance measurement module such as the distance measurement optical system and the light receiving section. Our aim is to provide a variable distance measurement range A position that can achieve the same effect as the previous one, but also allows you to easily understand the relationship between the distance measurement areas when observing the viewfinder and when shooting. .

[Means for Solving the Problems] The present invention provides a photographic lens having a zoom function, a focus detection device that performs measurement through the photographic lens, and a focus detection device that changes the size of a field frame displayed in a finder. a device;
The variable range measuring device is equipped with a device that zooms the photographic lens so that the angle of view is equivalent to the smaller one of the field frames after the distance measuring operation by the focus detection device.

In addition, devices that change the size of the viewing frame include LCD, BC
It is composed of electro-optical elements such as D.

Furthermore, the viewfinder magnification is variable.

[Function] According to the above configuration, the field of view frame displayed in the finder is variable, and the mouth movement is performed within the range of the large field of view.
By subsequent release, the photographing lens is zoomed according to the telephoto (telephoto) rule, and the photograph is taken within the range of the smaller field of view.In this way, an effect equivalent to relatively widening the a+ distance area that occupies the photographic screen is obtained. .

Embodiment ρJ1 The optical system of a single-lens reflex camera according to an embodiment of the present invention will be explained with reference to FIG.

In this embodiment, the photographic lens 1 having a zoom function is a four-group zoom lens. A quick return mirror 2 located behind the lens 1 has a function of dividing incident light into a viewfinder side and an AF sensor module side for automatic focusing. On the finder side, there is a focusing plate 3 with a surface that forms a real image equidistant with the film surface, and a display device 4 for displaying a field frame and an a1 distance area on the real surface of the finder. A pentaprism 5 and a finder eyepiece 6 are provided. This eyepiece lens 6 has variable zooming and variable finder magnification.

The viewing frame in the display device 4 is, for example, an LCD (Li
Quid Crystal Display) or ECD (Electrochromic Dis
The AF sensor module side is provided with a sub-mirror 7 for guiding light to the same side, and an AF sensor module 8 such as a CCD. There is.

Next, the control system of the camera will be explained with reference to FIG. This control system uses CPLJ to control the entire camera.
AFCPU II, an AFCPU 12 for AP, and a lens ROM 13 in which unique data of the photographic lens 1 is stored. The detection signal is input to CPIJII via the A/D converter 15.

The CPU II has a release 8F7 installed on the camera body.
16 signal was input, and when the release jo16 was pressed halfway, it was released! II optical distance measurement switch S1 is turned ON, and furthermore,
By pressing the button, the release switch S2 is turned on, the shutter is opened, and a photograph is taken.

Further, the zoom motor 18 for zooming the photographing lens 1 is driven by the output of CI)Lllll via the zoom motor driver 17, and the distance measurement area in the finder is driven via one driver for viewfinder display. The display device 4 is driven. The signal from the AF sensor module 8 is sent to the AF via the AF interface 20.
The output of the AFCPU 12 is input to the CPU 12, and the A
The motor 22 of Jl is driven. Furthermore, CP
A switch 23 is provided for giving a command to Ull to select a ranging area expansion mode (details will be described later).

Next, Fig. 3(a) shows the field of view frame and distance measurement area of the finder when looking through the eyepiece lens 6.
This will be explained using (b) and (c). Figures (a) and (b) show the relationship between the finder field frame d, distance measurement area f, and the subject when the same subject is zoomed from the wide-angle side to the telephoto side. Note that since the distance is measured through the photographic lens, the size of the distance measurement area f with respect to the photographic screen does not change. In the range-finding area expansion mode, the photographing lens is set to the wide field frame d shown in FIG. 5(a), and the eyepiece lens 6 is zoomed to increase the finder magnification as shown in FIG. 2(c).

With this finder magnification increased, the above al l? [Display the field of view frame e according to the magnification ratio of the u area. This field of view frame e is equivalent to the field of view frame d in FIG. 4B, which is the angle of view at which tA3 is actually shaded.

This distance measurement area f is displayed by the display device 4.

Note that in the state shown in FIG. 3(c), in reality, the eyepiece lens 6
Since there is a limit to the size of the field frame d, the periphery of the field frame d is obscured by the lens and cannot be seen clearly.

A distance measurement operation is performed in the distance measurement area f in the field of view frame d in the wide state of the photographing lens in Fig. 3(a), and then, by zooming, the field of view frame d in the tele state as shown in Fig. 3(b) is obtained. , The photographing operation is performed in this state.

As shown in FIG. 4, the visual field inner frame e may display only the frame lines on the display device 4, or the inner frame e and the frame d may be displayed on the display device 4.
It may be displayed by making the range opaque.

As another means of changing the size of the viewing frame, instead of the display device 4, as shown in FIG. It may be equipped with a member that can be moved in the direction.

Note that the field of view frame e may be displayed not only in the distance measurement area enlargement mode but also always displayed. In that case, the display device 4 does not use an LCD, ECD, etc., and the focal The frame within the visual field may be written directly on the plate 3, or the frame within the visual field may be drawn on a separate member by printing, vapor deposition, or the like.

Further, in the above embodiment, the eyepiece lens 6 zooms, but as shown in FIG. 6, a magnifying lens consisting of a concave and convex lens 6b is inserted into the fixed eyepiece lens 6a during the distance measurement area expansion mode. The viewfinder magnification may be enlarged.

Also, regarding the relationship between the focal length of the photographic lens 1, the photographing area, and the viewfinder observation area, the original photographic lens (
It is not possible to expand the distance measurement area over the entire focal length of the zoom lens) 1. For example, if the distance measurement area expansion rate is β and the focal length of the photographic lens 1 is fW to fT.
Then, the usable (photographable) focal length is f ・β
~ fT, and the focal length that can be observed with a finer is fw ~ f1, /β.

Therefore, when the shooting lens 1 is initially set to f/β to fT, when the focus area expansion mode is set, the shooting lens 1 automatically zooms to fT/β (
It will be rolled out). Then, fW~fT/β
The photographer determines the sideways glance within the range of .

Next, the sequence of the camera operation by the CPU 1, AFCPU 12, etc. will be explained based on the flowchart of FIG. 7.

First, when the release button 16 is pressed halfway, the JFI optical a1
Distance switch S1 turns ON and the camera is activated (#1)
, unique data of the photographing lens 1 from the lens ROM 13, that is, focal length, aperture value, etc., are input to the CPU II (#2), and then the film sensitivity (ISO) is input to the DX.
The code or manual setting data is input to the CPU II and stored (#3).

Next, focus area expansion mode (this is referred to as AFM)
Check if is selected (#4), and if it is normal mode and AFM mode is not selected,
FM=O, the AF (automatic focus) routine is entered, distance measurement information is taken in, focusing is performed, and (#5
), then a photometry routine is entered, )...light information is taken in, and aperture and shutter speed values for obtaining proper exposure are determined (#6).

Next, wait for the release switch S2 to be turned on by fully pressing the release button 16 (#7), and when this is turned on, the aperture is narrowed down to the set aperture value and the mirror 2 starts to be raised (UP) (#7). 8). When the mirror up and aperture are completed, the shutter (not shown) opens, and after the proper exposure has been given to the film, the shutter closes (#9
> ,! The light is completed.

When the distance measurement area expansion mode selection switch 23 is operated and the distance measurement area expansion mode is selected, the above #4
In this mode, the AFM becomes 1 and the process proceeds to steps after #1O-1. In this mode, first, the viewfinder magnification is changed by the eyepiece 6 (#1O-1), and the field of view frame e is displayed (#1O-1). 1O-2), then #11 to #1
Step 3 is similar to #5 to #7 described above. When the release switch S2 is turned on, the aperture is narrowed down, mirror 2 starts to move up, and the image disappears in the finder (#14).

Next, the CPU activates the zoom motor 18 via the motor driver 17 to zoom the photographing lens l toward the telephoto side so that the angle of view is equivalent to the inner field of view frame e.

That is, the focal length of fAl shadow lens l is varied (#
15) Furthermore, if the image point moves due to the above zooming, focus correction is applied (#16), and then,
The shutter is opened and closed in the same way as #9 above (#17
), fog light is completed.

Note that the steps #14 to #16 may be controlled simultaneously or the order may be reversed.

By performing the sequence operation described above, when the i(l distance area expansion mode) is selected, an effect equivalent to that of relatively widening the distance measurement area can be obtained.

Furthermore, in the above sequence, in the ranging area expansion mode, the enlargement ratio is not limited to one, and the size of the ranging area may be variable to a plurality of sizes, in which case,
An enlargement ratio selection mode (not shown) is required in #10-1.

[Effects of the Invention] As described above, according to the present invention, since there is a mode in which the focal length of the photographing lens is varied to the angle of view that matches the smaller field of view frame after release, the distance measuring optical system The distance measurement area can be relatively widened without changing the distance measurement module or distance measurement module, making it possible to take accurate photographs, and it is also advantageous in terms of space in terms of camera configuration and design. .

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of the optical system of a single-lens reflex camera according to an embodiment of the present invention, Fig. 2 is a block diagram of the control system of the same camera, and Figs. FIG. 4 is a diagram showing an example of display of the viewfinder's viewing frame, etc. FIG. 5 is a diagram showing an oval formation as a means of changing the viewing frame, and FIG. The figure shows an example of the pond in the eyepiece section, and FIG. 7 is a flowchart showing the operation sequence of the camera. l...Photographing lens, 4...Display device: 〃, 11...
CPU, 16... Release button, 17... Motor driver 18... Zoom motor, 23... Jll distance area expansion mode selection switch.

Claims (3)

[Claims] (1) A photographic lens with a zoom function, a focus detection device that measures distance through this photographic lens, a device that changes the size of the field of view frame displayed in the finder, and after the distance measurement operation by the focus detection device . A distance measuring range variable device comprising: a device for zooming a photographic lens to obtain an angle of view equivalent to the smaller one of the field frames. (2) The ranging range varying device according to claim 1, wherein the device for varying the size of the field frame is comprised of an electro-optical element. (3) The ranging range variable device according to claim 1, characterized in that the finder magnification is variable.